HTTP Error 403: Forbidden upon accessing Web Service

HTTP Error 403: Forbidden upon accessing Web Service

We are currently doing (exposing) a webservice written also in Outsystems deployed in the Java platform. Upon testing (consuming), we are able to import the webservice in a .NET stack platfom but is not able to use it (i.e.: Preparation, function) because it returns a 403: forbidden error.

The webservice does not have any certificate defined and so is the server.

We have tried to isolate the issue by:

Consuming the webservice on the same server - OK

Deploying the webservice on a .NET stack and consuming on the Java stack - OK

Deploying the webservice on a .NET stack and consuming on the .NET stack - OK

The webservice was initially deployed on premise and has tight security features (which might be the cause of the error) then decided to deploy this on the cloud - however, this also resulted to the 403 error.

The webservice is deployed on v9.0 and is being test consumed by v9.1.